Aamir Amanullah, National SAMSA’s membership co-chair and MS2 at Temple University School of Medicine, recently reviewed the following study in the The Journal of the American Heart Association: “Incidence and Progression of Coronary Artery Calcium in South Asians Compared With 4 Race/Ethnic Groups”
South Asians are one of the fastest-growing minority populations in the United States, but compared to other racial and ethnic groups in America, they’re also several times more likely to be diagnosed with Type 2 Diabetes Mellitus (T2DM), Myocardial Infarctions (MIs), and have been found to have greater mortality rates of cardiovascular (CV) disease. Atherosclerotic CV disease is highly prevalent in South Asians, and it’s becoming imperative to understand and establish independent risk factors for atherosclerotic CV disease as the population rapidly grows in the United States.
The Journal of the American Heart Association published a study by Kanaya and colleagues comparing Coronary Artery Calcification (CAC) progression between South Asians and 4 other ethnic groups living in America (Whites, Blacks, Latinos, and Chinese Americans). The CAC is obtained by CT imaging and has gained ground as a unique risk factor to help predict heart disease and mortality rates in different US populations. Previously, no studies had analyzed consecutive CAC measurements to determine CAC incidence and progression in the South Asian American population. The authors used two large, publicly available data sets to make comparisons between South Asians and other US ethnicities: MASALA (Mediators of Atherosclerosis in South Asians Living in America) and MESA (Multi-Ethnic Study of Atherosclerosis) and utilized univariate and multivariate modeling for statistical analysis.
After accounting for usual CV risk factors like age, physical activity, BMI, hypertension, statin use, diabetes mellitus, etc. Kanaya et al found that South Asian men had significantly greater annual CAC change when compared to Black, Latino, and Chinese American men, but South Asian men had similar annual CAC changes compared to White men. Researchers did not find differences in CAC incidence nor progression between South Asian women and the other women from the MESA study. The authors state that before accounting for traditional CV risk factors: longer residence in the USA, smoking, and higher alcohol consumption were associated with greater CAC, while higher income and CAC change were inversely associated, and that exercise and caloric intake were not associated with CAC change. However, after accounting for typical CV risk factors, sociodemographic and behavioral factors were not found to be associated with CAC progression.
Kanaya et al. concluded by suggesting CAC presence and progression data can help guide healthcare providers to predict heart disease and MI risks in South Asian Americans as well as improving medication and preventative treatment plans for South Asian patients, and this is a reason more research about CAC in South Asians is needed. They also highlighted the need for further longitudinal, prospective studies to improve our understanding of CV disease advancement as a whole in the South Asian American population. The authors noted some limitations of their study due to the nature of the cohorts sampled in MASALA. The MASALA study collected data from only 2 locations in the US: the Bay Area at the University of California, San Francisco (UCSF), and the greater Chicago area at Northwestern University. Additionally, the MASALA participants were primarily first-generation immigrants from India with higher socioeconomic statuses. These limitations may reduce generalizability to all South Asian Americans. The authors also suggested that since study participants were healthy (participants with prior CV disease were excluded), CAC progression may be worse among the general South Asian American population.
Taking all of this into account, we still have so much more to learn about CV disease and progression in the South Asian American population. For both current and future medical professionals, this is not only a very exciting topic to explore, but also a very important one as the South Asian population continues to rapidly grow and expand in the United States!
Kanaya AM, Vittinghoff E, Lin F, et al. Incidence and Progression of Coronary Artery Calcium in South Asians Compared With 4 Race/Ethnic Groups. J Am Heart Assoc. 2019;8(2):e011053. doi:10.1161/JAHA.118.011053